I usually tuck annuals into my perennial beds as well as in pots for additional color rather than creating a whole bed of just annuals.
However, last summer, I saw a lovely bed in my neighborhood devoted entirely to annuals. It was full sun and composed predominantly of pink and blue flowers. At the back were tall cleome, commonly called spider plant. It is an easy-care annual that self-sows and often comes back year after year. There were also tall cosmos in pink and white shades. Both the cleome and the cosmos have foliage that have an airy look so they are compatible together in a massed planting.
In front of them was annual blue salvia and the annual dark purplish-pink Gomphrena, commonly called globe amaranth, which holds its color when dried.
A good combination for a lasting dried flower arrangement is the aforementioned annual blue salvia ‘Victoria’ paired with the purple/pink heads of globe amaranth. Cut the flowers in the fall, strip the leaves from the stems, tie the flower stems together tightly with a rubber band, and hang upside down to dry in a dark place like a closet. They retain their colors beautifully.
The option of drying some of these annuals later in the season, made this bed of annual flowers even more appealing to me when I saw the pretty display.